Design considerations for Parts for 3D printing

I was wondering if there are any good links that discuss design do's and don'ts for 3D printing. I haven't even built my printer yet but I'm looking at one of the parts I've designed and I'm not sure if its printable. Any tips, suggestions or links would be much appreciated.

I think that the primary rule is that all overhangs need to be 45 degrees or less.

Large overhangs, even at less than 45, need support structures.

There is also a minimum wall thickness / hole size that most people can print, but that is very printer-dependent.

And of course, print bed volume. This is something you'll need to take into account if you want to make the object more universal, since a lot of people have Makerbots, which have a much smaller volume.

If you're not sure of your design, post it here, or on one of the other forums for comment.

I'm really enjoying designing parts for the printer, and i'm learning a lot on the way (which is the point of doing it of course), but I would love to know if there are any guides, books or such which can help me improve how to think about design.

Quite often I will have an idea and start to throw together a proof of concept only to realise there is something in the design I have overlooked. Most of the time I need a dose of common-sense, or a bit more patience to think through the design, and most times I learn a lot from the process itself, which is all part of the reason to do it in the first place. However, it would be great to know of anything that can help develop the process of designing itself!

I saw the following sketch from a Makerbot blog post the other day which exemplifies the kind of thing I think i'm looking for:

For the engineers and designers out there this may seem simplistic - but this kind of thing can be really useful for the hobbyists amongst us. I would really like to collect these kind of things together over on the development tracker so people starting out can quickly learn how to design for 3D printers.

I actually realized the problem after designing this clip. I guess I need to start printing to learn the limitation of 3D Printing and work with it.

In any case I am using an Application called Catia V5, its what's used in design engineering in Automotive, Aerospace etc. I use it at work for Aircraft Tooling Design most of which is all focused around Machining drill fixtures etc So this is all very new to me